December 15 – Clam bake

Today’s factismal: An adult giant clam can get 75% of its food from algae living inside its skin.

One of the staples of Saturday afternoon movies is the deadly giant clam. As our hero swims fearlessly underwater through the coral reef surrounded by colorful fish and fierce pirates, suddenly his foot is caught by a giant clam. He struggles fiercely and is only able to free his foot and head for the surface after stabbing the clam to death with his handy bowie knife. But how realistic is that?

This man-eating clam is waiting for its next victim (My camera)

This man-eating clam is waiting for its next victim
(My camera)

It turns out that there is some truth in that scene, but there’s a lot more fiction. Let’s start with the true part: in coral reefs from the shores of Australia to the Philippines lives a giant bivalve that was once known as the man-eating clam; today, we call it by the less evocative name of giant clam. And the giant clam certainly deserves its name; this enormous bivalve can grow to be more than four feet across and can weigh as much as 700 pounds!

A three-foot long giant clam (My camera)

A three-foot long giant clam
(My camera)

But tales of men being captured and eaten by the clams are far more fiction than fact. The giant clam closes very slowly and would be unlikely to catch any but the least wary swimmer in its grasp. In addition, the larger clams can’t even close completely, allowing swimmers to wriggle free with no trouble. Finally, the giant clam is a filter feeder, with no way to digest any large prey that might accidentally get caught when it closes its shell.

However, that last statement isn’t completely true. The giant clam starts its life as a filter feeder, pumping water across its gills using a siphon and living off of the sediment and other goodies that get trapped inside. But by the time it has settled down for a life as a responsible adult clam (when it is about a tenth of an inch long), the clam has started to play host to a type of algae known as zooxanthellae (“little yellow critters”). These algae live inside the clam’s skin in special sacs surrounded by blood vessels. The giant clam will open up and spread its mantle to let the algae get the sunlight as it feeds them waste products that the algae use as food; the algae in turn will combine those waste products with sunlight to make food for the giant clam. A large giant clam will get as much as 75% of its energy from the algae and only about 25% from the goo it filters out of the water.

The zooxanthellae live in the colorful spots on the giant clam's mantle (My camera)

The zooxanthellae live in the colorful spots on the giant clam’s mantle
(My camera)

These giant clams are an amazing example of symbiosis and form an important part of the reef system where they live. Unfortunately, their reputation (and large closing muscle) have made them a popular target for poachers who can sell them for several thousand dollars each. And that’s why the Reef Environmental Education Foundation would like you to report any giant clams (or any other reef critters) that you’ve seen. If you’ve seen them alive, then they want to hear from you. And if you’ve seen them dead and being sold in the market, then they really want to hear from you. To learn more about their mission to save the giant clam and other reef animals, swim on over to:
http://www.reef.org/

December 12 – Merry Techmas!

Today’s factismal: X-mas was used as an abbreviation for Christmas around 1100 AD.

Back in 1021, there wasn’t much to write on (to be fair, there weren’t many people who could write on what there was to write on, but that’s another topic to write on). Papyrus was common in Egypt and many Mediterranean countries, but rare outside of there. Vellum (a prepared animal hide) was used for important works in Europe but was fairly expensive. For most daily commerce, wooden boards and slates were used, along with wax tablets in cooler regions. But in every case, these writing surfaces had one thing in common: space was limited.

As a result, the folks who wrote often used abbreviations. One of the more common ones was the use of Χ (the Greek letter “chi”) as shorthand for the word “Christ”. For example, monks writing an account of the exploits of St. Christian of Clogher would refer to him as “Χn d Clogher”. Similarly, Christian of Oliva would be written as “Χn D Oliva”. And Jesus Christ was frequently noted by the combination of two Greek letters (chi and rho; first used by Emperor Constantine as a symbol for his troops), creating the “labarum” ☧. So ever since early Christianity, Christ’s name was abbreviated and Christmas has been written as Χmas.

Of course, I only know this because those monks passed their knowledge down using the best technology of the day. And they also passed along the knowledge of how to use that technology. Today we are more dependent on technology than ever. And we are fortunate in that we don’t need monks to pass the information along – we need geeks. And that brings us to the citizen science opportunity for today: Free Geek. This is a group of geeks dedicated to spreading technology by making it affordable. They take old electronic equipment (computers, cell phones, etc.),and train disadvantaged youth to refurbish it; the equipment is then sold or distributed to at-risk communities. If this sounds like something that you’d like to get involved in, then set your browser to:
http://www.freegeek.org/

December 11 – Aloha!

Today’s factismal: Mauna Kea means “white mountain”.

There’s no doubt that Hawaii is a beautiful place. It is covered with rainforests, surrounded by colorful reefs, and filled with brightly colored animals, plants, and tourists. But perhaps the most beautiful part of Hawaii is Mauna Kea, the 33,100 ft tall mountain that is both the base for the state’s largest island (the eponymous Hawai’i) and the world’s tallest mountain. (Everest is a mere 15,260 ft when measured from its base to its summit; if Everest were placed beside Mauna Kea, it wouldn’t even reach the sea surface!)

Mauna Kea covered with snow (Image courtesy of USGS)

Mauna Kea covered with snow
(Image courtesy of USGS)

And that marvelous mountain is a wonder in many ways. Formed from a shield volcano, it started life a million years ago as a mere seamount. Fed a steady diet of basalt lava by a mantle plume, it grew quickly into the massive presence that we know and love today. Though its last major eruption was more than 200,000 years ago, it could still erupt and add a few more feet to its impressive total. But even more exciting than the possibility of a future eruption is the reality of its peak. The top of Mauna Kea rises an impressive 13,803 ft above sea level, which is tall enough to put the peak into a freeze cold enough to create a permafrost zone at the very summit! And if that’s not enough, for about nine months out of every year, Manua Kea is topped by a white blanket of snow that can be several feet thick. And it was that white coating of snow that gave the peak its name; in Hawai’ian, “Mauna Kea” means “white mountain”.

Of course, you don’t have to live in Hawaii to get snow (as most of the US can attest this week). And if you do happen to get some snow this winter, then there’s a group of scientists that would love to hear from you. Called Snowtweets, they are trying to track the amount of snow that falls so that they can improve forecasts. All you have to do to participate is head outside after a snowfall, use a ruler to measure the amount of snow that fell, and send out a tweet with the amount of snow that fell:
#snowtweets <snow depth in cm., in. or ft.> at <postal code, ZIP code or latitude, longitude>

To learn more, head on over to:
http://snowcore.uwaterloo.ca/snowtweets/

December 10 – Stink, Stank, Stunk

Today’s factismal: Pâté made with stink bugs and chicken livers is considered a delicacy in many parts of the world.

It is the holiday season once again, and we all know what that means – parties! And one of the most traditional of all holiday parties is the potluck supper, where everyone brings a dish to share with the others. If you’d like to stand out this year from the endless parade of green bean casseroles and turkey à la King casseroles, then may I suggest a nice chicken liver and stink bug pâté? According to those who have tried it, the roasted stink bugs add a certain bouquet to the mix and raise it from the ordinary into something truly unusual. (I wouldn’t know – I’m allergic to insects.)

Eating stink bugs isn’t as strange as it might sound. Not only are insects a good source of protein, by eating them we take back a little of the food that they have stolen from us. And that’s exactly what most stink bugs do – steal food. That’s because they are “true bugs”, with a mouth designed like a hypodermic syringe that can pierce through tough plant or animal skins and suck out the juicy insides.

Brown marmorated stink bugs, ready to be made into pate (Image courtesy USDA)

Brown marmorated stink bugs, ready to be made into pâté
(Image courtesy USDA)

Among the most noxious of the stink bugs is the brown marmorated stink bug. This critter isn’t so bad in its homeland of China and Japan, where a wasp likes to use it as food (see – I told you they were tasty!). But it is spreading rapidly here in North America after being accidentally introduced in 1998. It is now found across the entire eastern United States. Though it is naturally most active in the spring and summer, they can be found more easily in the winter when they migrate into homes to hibernate. They will crawl through open doors, windows, soffits, and just about any opening that they can squeeze their body through in the fall and then wait for spring, snug as a bug in a rug (mainly because they are). If the house warms up enough, then the stink bug may become active and head for the nearest light fixture, which is your chance to catch them.

If you aren’t interested in roasting the stink bug for diner (and I can’t really blame you), then you could always report it to the folks at the Stop Brown Marmorated Stink Bugs web site. They’ll use your information to help the USDA and other agricultural groups fight back against this new pest. To report a bug, scitter on over to:
http://www.stopbmsb.org/

December 9 – Amazing Grace

Today’s factismal: Grace Hopper, the person who wrote the first compiler and named the computer bug, was born 108 years ago today.

There is no doubt that women today have a tough row to hoe; they face an uphill battle in every field from psychology to medicine to particle physics. But that battle would be even more difficult if it weren’t for the efforts of women such as Rear Admiral “Amazing Grace” Hopper, who fought ignorance and sexism while also helping us to win World War II.

Grace Hopper with a UNIVAC that she taught to do COBOL (Image courtesy IBM)

Grace Hopper with a UNIVAC that she taught to do COBOL
(Image courtesy IBM)

Hopper was born on December 9, 1906, in New York City where she quickly demonstrated her aptitudes at the age of seven by taking apart alarm clocks to see how they worked. She stayed curious and kept learning, so much so that she was admitted to Vassar at the age of 17 and then to Yale, where she earned her PhD in 1934. By that time she was already a professor at Vassar, a post she would keep until the outbreak of World War II which changed everything; she forced the Navy to enroll her as a midshipman (they didn’t want her because she was too small) and soon graduated at the top of her class.

At the time, the US Navy was using analog calculators to predict the tides and perform other complex calculations. And the most important of these was the Harvard Mark 1 Automatic Sequence Controlled Calculator. This 10,000 pound behemoth was 816 cubic feet of gears, cams, and cogs, powered by motors and controlled by 1,440 switches connected with 500 miles of wire that made 3,000,000 connections in the machine. And what did this mass of magnificent machinery do? After the programmers had spent the better part of a day setting up a math problem by punching holes in a paper tape, it could chug through it at the rate of six seconds for each multiplication. (If this seems slow to you, remember that the alternative was having a person do the calculation by hand on paper. When the numbers involved are 23.7890123546823 x 0.183764527829, you are willing to take a little time…)

For each new problem, a brand new paper tape had to be made with new instructions and the switches reset. But if any of the steps was wrong, then the whole tape and all of the switches had to be examined to find out which one was causing the problem. Because the commands were written only as a series of holes in paper (what we would call “ones and zeros” today), this was a tedious, painstaking affair that often took much longer than punching the original program did. It was that process, which she and others repeated thousands of times during the war, that gave her the insight of a compiler: a program that took already coded subroutines and followed a set of “ordinary language” instructions to call up the subroutines in a specific order. When her colleagues told her that such a program couldn’t be written, she did so, creating the very first compiler in 1951.

She soon developed improved versions of her compiler, relying on free copies that had been given to customers (the first open source programming!). By 1959, Hopper’s compiler was used as the basis for COBOL, one of the first and most influential computer languages. (Remember Y2K? It didn’t happen because of people who knew COBOL.) After that, Hopper went back into the Navy where she served until she retired as a commander in 1966 at the mandatory retirement age of 60.

Grace Hopper at the time of her final retirement (Image courtesy US Navy)

Grace Hopper at the time of her final retirement
(Image courtesy US Navy)

But the Navy decided that they needed her too much and waived the rules to let her come back, at which point she developed standards testing for Navy computer systems and promoted the idea of distributed computing. (Ever hear of the cloud? Yeah, that was her idea.) And she kept having great ideas until she was once again forced to retire at the age of 65. That time, the Navy only lasted six months before they asked her to come back at the rank of captain. She was soon promoted to Commodore (which became Rear Admiral) and kept in the Navy by special act of Congress until she was 79 years old. When they finally let her go, she was the oldest active-duty commissioned officer in the United States Navy.

Hopper showed the Navy and the world that women have what it takes to be the best programmers around. She led the field, even when it didn’t want to be led, and helped create the modern technological wonderland that we live in. And there is no better way to celebrate her birthday than by taking part in the Hour of Code 2013. This tech challenge happens every year and kicks off Computer Science Week (which takes place this week in honor of Grace Hopper). At the Hour of Code 2013, they have resources for educators, students, and citizen scientists – so there’s fun for everyone! To get started, set your browser to:
http://csedweek.org/learn

December 8 – Smell of success

Today’s factismal: The chemical responsible for a smell is called an oderant; the sensation of smelling that chemical is called an odor.

As we’ve seen before, scientists can be pretty finicky about their language. But the language of the senses is particularly tricky, and no part of it is more exacting than the description of how our sense of smell works. Part of that is because our sense of smell is particularly acute; where we can describe most tastes using just five different descriptors, more than 140 different distinct smells have been defined. And part of that is because the process of detecting a new oderant is particularly complex.

So how do we detect these chemical signals? It all starts with the oderants. These chemical bundles are small enough to be carried along on air currents and volatile enough to be thrown off of the smelly thing in large enough numbers to be detected. Once those puppies are in the air, they diffuse out; to get an idea of how this works, plop one drop of food coloring into a big bowl of water and watch. The smell of that nice new scented candle you just bought fills the room the same way that the food coloring slowly fills the bowl of water.

Once you have oderants in the air, you need to have something to detect them; for people, that’s a nose. More specifically, it is the olfactory epithelium (“smelling {skin}”) that lies within our noses. The nose starts by filtering out dust and bring the temperature of the incoming air to within one degree of the body temperature. The air is then passed over two turbinates (one on each side) that cause the air to swirl about so that the oderants in it are given every opportunity to get stuck in mucus. That’s right – that icky stuff that creates runny noses is also the stuff that is responsible for our ability to smell!

The oderants are trapped within the mucus, but it also traps dust and germs. Fortunately, the mucus contains antibodies that kill off the germs; if this weren’t the case, then infections could spread from our noses directly into our brains. (This is why doctors frown on nose piercing; it can provide a channel for infection that skips the mucus.) The oderants filter through the mucus and are finally presented to the 1.6 square inches of olfactory epithelium that a human uses to smell. (Don’t be too smug about the size of your olfactory epithelium; a dog has one that is about seventeen times larger and that has 100 times the nerve density that you do.)

As you might guess, with a system this complex, there are a lot of things that can go wrong. Rapid changes in temperature can cause the blood vessels in the turbinate to change size, creating “brain freeze”. Nerve cells die off with old age, leading to a general decrease in sensitivity. Exposure to cigarette smoke and other pollutants can kill off nerve cells, again causing loss of the sense of smell. And people who suffer from brain cancer or other diseases frequently experience changes in their sense of smell. And that last is something that medical researchers desperately want to know more about. At the Smell Experience Project, researchers are asking for stories from people who have had a change in their sense of smell. The stories will be used in medical publications and teaching. If you’d like to participate, then go to:
http://psych-institute.med.nyu.edu/research/submit-story

December 7 – Getting the message

Today’s factismal: Your cells contain about five times as much RNA as DNA.

In the world of biology, DNA is king. It carries the genetic code that helps determine the difference between a man and a mouse.It determines what protein will be made and when. And DNA may even determine how long your cells (and therefore you) live by the length of the telomeres that make up the end of a DNA strand. But no kingdom can be run by the king alone, and the cell is no different. If DNA is the king, then RNA is the royal messenger.

Like DNA, RNA is made up of nucleic acids. But unlike DNA which is famously double-stranded, RNA is just a single strand copied from sections of DNA. But what a strand it is! Some types of RNA transport amino acids in the cell and get them ready for use; these are called, logically enough, transport RNA or tRNA. Other types of RNA assemble the amino acids into proteins; because they are found in the ribosome (a sort of cellular protein factory), they are call ribosomal RNA or rRNA. And other RNA carries instructions on how to assemble those protiens; because it is the messenger of the cell, it is call messenger RNA or mRNA.

As you might guess, all of those different types of RNA add up to be quite a lot of information floating around in your cells. Where DNA accounts for about 1% of a cell’s weight, RNA makes up nearly 5%! But that bulk comes with a price; where the DNA is permanent, the RNA is constantly being built up, used, and then broken down into its parts to be used again.

But perhaps the most amazing thing about RNA is how little we know of how it functions. We only know a few thousand out of the several million different viable configurations of RNA; that lack of knowledge is what keeps us from developing a cure for the common cold (which is transmitted by the RNA of a virus) or curing some forms of cancer. Of course, where there’s a gap there’s a research project. And this one is called EteRNA. In this game-based project, you’ll build different RNA strands which will then undergo computer simulation to see if they are viable. And every week, the most viable ones will actually be synthesized to see if our prediction of how they work is right! If you’d like to get into the game, then head on over to:
http://eterna.cmu.edu/web/